Formation of Double Roughness Structure on PVDF/PMMA Blended Film Using Atmospheric Pressure Low-Temperature Plasma

Oil repellency by the super hydrophilic structure on the surface of snail shells and super water repellency by the double roughness structure on the surface of lotus leaves are well known as specific examples of biomimetics. We have formed super hydrophilic structures on the surface of poly(methyl methacrylate) (PMMA) films by irradiating Atmospheric pressure low-temperature plasma (APLTP), and have confirmed an antifouling function like a snail's shell. On the other hand, it is expected to be difficult to form a double roughness structure observed on the surface of a lotus leaf, which has water repellency, in pure PMMA films. In this study, we examined about the formation condition of the double roughness structure, using APLTP and poly(vinylidene fluoride) (PVDF) / PMMA blended films. The double roughness structure can be formed when the power supply was 7.2 kJ in a film with a PVDF/PMMA blend ratio of 70/30 wt%. However, the improvement of contact angle was only 10° because insufficient growth of the submicron-order microstructure. We will study to further improve the contact angle continuously by optimizing the conditions of APLTP process and polymer blend.